隧道内的V形，人字形简单悬挂滑动环不卡滞。
参考答案：对
．The terrible flood swallowed the village ________ the villagers could get away. No one survived it.
A．after
B．as
C．since
D．before
直肠肛管周围间隙不包括（）
A.坐骨直肠间隙
B.骨盆直肠间隙
C.直肠后间隙
D.肛管间隙
